Background: Maternal nutrition has a strong influence on singleton and twin birthweight. This study evaluated the association between twin birthweight and maternal pregravid body mass index (BMI), weight gain, and cravings and aversions. Information was also obtained regarding sources of nutrition advice and advised versus actual weight gain.
Methods: This study is based on data from interviews with 928 mothers of twins. Univariate analysis included comparisons by source of nutritional advice, birthweight categories, and categories of cravings and aversions. Multiple logistic regression was used to formulate models for mean twin birthweights > 1,500 g and > 2,500 g.
Results: Mothers who received their nutrition advice from a registered dietitian had the highest weight gains and the lowest proportion of birthweights < 1,500 g. For mean twin birthweight > 2,500 g, the final model included prematurity, pregravid BMI, and weight gain; for birthweights > 1,500 g, the model additionally included maternal age and aversions.
Conclusions: Maternal pregravid BMI and gestational weight gain were shown to be important factors influencing twin birthweight. Nutrition advice, particularly from a registered dietitian, may be vital in assuring adequate weight gain, and therefore better birthweights, for these high-risk pregnancies.